>I wish one implementation triumphed over the othersThat would be terrible. Part of the nice things of CL is that you can choose the implementation according to what you need. For example ECL if you want to embed your lisp code with C code. ABCL if you really need to call lots of Java libs (or have Java code call your Lisp code easily), and so on. We're talking about mature, proven, tested implementations.
If one implementation triumphed over others, over time we'd be in a position similar to, say, Python or Clojure, where there is only one or two implementations, besides some experimental implementations, and nothing else.
Something that needs to be mentioned is that CL is truly standardized; if you have a code written in Common Lisp, chances are it will compile straight away on most of the implementations (ECL, ABCL, SBCL, etc), with no change needed. So having many implementations does not mean there is any kind of fragmentation in the language.
>and CL progressed beyond its ANSI standard.
CL is one of the most extensible languages out there, so it has already progressed way beyond the ANSI standard. The standard doesn't need modification to support new things. There are already many libraries giving you things that are not in the standard (like sockets or threads) but in a portable and standarized way.